The invention relates generally to overhead valve train assemblies and more particularly to overhead valvetrain assemblies having stabilized rocker arms.
In many conventional overhead valvetrain configurations, one end of a rocker arm engages a lash adjuster, the opposite end engages a valve stem and a roller or other friction reducing device in the middle of the rocker arm engages the camshaft. So configured, there is no fixed axis about which the rocker arm pivots and thus the rocker arm cannot be stabilized by being mounted on a shaft. Rather, the rocker arm must be and is maintained in its proper position by cooperation between a convex, hemispherical feature on the lash adjuster and a complementary concave, hemispherical feature on the rocker arm. This mounting arrangement has not always proven to be satisfactory as side loads on the assembly may result in the rocker arm moving out of its desired, operating position. Additionally, there are inherent limits to rocker arm rotation and valve lift which, if exceeded, will again result in the rocker arm moving out of position.
From the foregoing discussion, it is apparent that improvements in the art of overhead valvetrains and lash adjusters are desirable.